Closure cap



Oct. 25, 1960 Filed July 15, 1959 R. B. WHITE ETAL CLOSURE CAP 2Sheets-Sheet 1 Oct. 25, 1960 R. B. WHITE ETAL 2,957,595

CLOSURE CAP Filed July 15, 1959 z Shoots-Sheet 2 120 g5;- r5: 6 er cea reic/za am M WW United States Patent Ofifice Patented Oct. 25, 1960CLOSURE CAP Roger B. White, Winnetka, and George F. Chaplin, ElmwoodPark, Ill., assignors, by mesne assignments, to Continental Can Company,Inc., New York, N.Y., a corporation of New York Filed July 13, 1959,Ser. No 826,610

4 Claims. (Cl. 215-40) This invention relates, generally, toimprovements and innovations in closure caps of the press-on, top-sealtype for hermetically closing and sealing glass containers. Moreparticularly, the invention relates to such closure caps which whenlifted or pried up at one point will snap ofi from the container withoutbeing permanently distorted or deformed, and which may be repeatedlyreplaced and retained on the container by virtue of a plurality ofcircumferentially spaced detents which grip the exterior of the rim orlip of the container just beneath the sealing finish thereon.

Press-on type closure caps are applied by being pushed down or presseddown on the container as distinguished from being rotated or turned downas in the case of screw caps or lug caps, which may also be of thetop-seal type. Press-on closure caps of the top-seal type are broadlyold and have been extensively used for sealing glass containerscontaining food products such as jelly, peanut butter, cheese spread,pickles and food products of all types. For example, press-on closurecaps of the top-seal type are shown in Patent 2,501,976. The upper edgeor surface of the rim of a glass container on which such caps are used,provides the so-called sealing finish. A gasket formed of rubber-likeresilient material carried in the top of the closure cap fits down onthis sealing finish so as to form a hermetic seal thereon. In applyingsuch caps to filled containers, a small headspace is left unfilled atthe top of each container which becomes filled with steam vapor when thecap is initially applied and pressed down in the capping machine. Thehermetic seal which is initially formed due to mechanical pressure isperfected and maintained when the steam or vapor in the headspacecondenses creating a vacuum.

Heretofore, when closure caps of the press-on, top-seal type wereremoved, they were often distorted or bent incidental to being priedoff. As a result of being thus substantially bent or distorted, thesecaps would not completely cover or close the container on beingreapplied as a dust cover when only a portion of the contents had beenremoved. Rather, the caps merely sat or rested on the tops of the glasscontainers and normally an open space was left at the place where thecaps had been bent up in being pried ofi.

In spite of this drawback, closure caps of the presson, top-seal typehave been extensively used for a number of years since: they areinexpensive; can be machine applied at high capping rates; providepermanent hermetic seals which rarely fail; and, form attractiveclosures.

The object of this invention, generally stated, is the provision ofimproved press-on, top-seal type closure caps for glass containers whichretain all of the desirable features of prior caps of this type but arecharacterized in that upon being pried oif at one point, instead ofdistorting or bending, the entire cap snaps off from the container withpractically no permanent distortion.

A further important object of the invention is the provision of press-onclosure caps of the top'seal type which have a plurality of detents ofsuch location, number and formation that they serve to properly orientor locate the closure caps on the containers during initial application,and serve to firmly grip the exteriors of the glass containers andthereby firmly retain the closure caps" in place when they are reappliedto the containers soas to serve as covers and keep the containerstightly closed.

Certain other objects of the invention will, in part, be obvious andwill in part appear hereinafter.

For a more complete understanding of the nature and scope of theinvention, reference may now be had to the following detaileddescription thereof taken in connection with the accompanying drawings,wherein:

Fig. 1 is a side elevational view of a glass container hermeticallysealed with a press-on, top-seal closure cap constituting one embodimentof the present invention.

Fig. 2 is a top plan view of the closure cap shown in Fig. 1;

Fig. 3 is a bottom plan view of the closure cap shown in Fig. 1 removedfrom the container;

Fig. 4 is a fragmentary detail sectional view on enlarged scale taken online 4-4 of Fig. 3.

Fig. 5 is a view similar to Fig. 4 but taken on line 5-5 of Fig. l andshowing the manner in which the top seal gasket and detents interfitwith the finish and side wall, respectively, of the glass container; and

Fig. 6 is a detail sectional view corresponding to Fig. 5 and takenthrough a modified form of the closure cap held in sealing relationshipon a straight sided tumbler.

In Fig. 1 a glass container 5, such as an ordinary jelly glass ortumbler having a bead finish, is sealed with a closure cap 6. This foodpackage illustrates but one of a wide number of large volume uses of theclosure caps forming the subject matter of this invention. The

invention pertains to certain specific features of the or printed withtrademarks, brand names, etc., while the V closure cap 6 which will nowbe described in connection with Figs. 2-5.

The closure cap 6 comprises a cap body or shell having a top panelportion 7 (Fig. 4) and a depending skirt portion designated at 8. Aninturned bead formation, indicated generally at 10, is integrally formedon the bottom of the skirt 8 and it is in connection withthis head 10that the novel features of the invention reside.

Cap bodies or shells of the type used in making cap 6, can be stampedout from suitably coated tin plate, although other materials may beused. The machinery and methods for stamping out the cap bodies orshells, and then forming the bead 10, are broadly old and do not form apart of the present invention. Usually, the tin plate is enambled on theexterior and often decorated interior is enameled or coated with a knownlacquer formulation so as to form a protective coating on the interiorof the cap body or shell and give the interior an attractive appearance.Usually white, or off-shade White, enamels are used on the interior,although other shades and colors may be utilized.

In addition to the shell, the second main element or component of theclosure cap 6 is a resilient, rubber-like top seal gasket indicatedgenerally at 11. I

In the particular cap shown in Figs. '2-5, the top panel has acontinuous annular shoulder 12 located radially inward of the peripheryof the cap so as to define the inner wall of a gasket retaining channel,the outer wall. being defined by the rounded portion 13 of the cap shellwhere the side wall or skirt 8 joins the top panel portion 7. The gasket11 may be of the flowed-in, plastisol type. This type of gasket and thedetails of the retaining channel therefor and the so-called inner thinfeather-edge 14 thereon, are described in detail in Zipper Patent2,841,304.

The hollow bead 10 is integrally formed on the bottom of the skirt 8 bya series of forming operations of generally known type using generallyknown dies and equipment. While the forming technique and equipment aregenerally known, the hollow head 10 incorporates certain innova: tionswhich make the cap 6 different in the above-mew tioned significantrespects from press-on, top-seal caps of the prior art.

Referring first to Fig. 3, it will be seen that'the bead 10 iscircumferential or continuous and it will be noted that it contains sixdetents 1515 each of which is of equal length, and equally spaced apart.Except for minor variations coming within predetermined tolerances, thedetents 15 are all identical. There may be fewer or more than sixdetents, but six is a preferred number. in the cap shown the combinedlengths of all six detents equals approximately 36% of the innercircumference of the bead 10. However, this relationship may vary from30-42% as a preferred range, with the individual detents occupying from7% of the inner circumference of the bead as a preferred range. When adifferent number of detents are used, the preferred length of eachdetent is still from about 5 to 7% of the inner circumference.

Referring now particularly to Fig. 4, it will be seen that this crosssection is taken midway through one of the detents 15. Intermediate thedetents a transverse cross section through the bead 10 as at bb in Fig.3, would show it to be hollow and generally circular, this formationbeing indicated in broken line at 16 in Fig. 4. Adjacent the end of oneof the detents 15 a cross section as at aa would show the detent asrepresented by the broken line designated at 17 in Fig. 4. It will beseen that each detent 15 at the middle portion has cross section whichis generally fishhook shaped as shown in Fig. 4. That is, it has acurved bottom portion 18 and a generally straight shank portion 20 afterthe manner of the conventional simple fishhook. The arcuate portion 18has substantially the same radius of curvature as that of the hollowhead 10. The shank portion 20 will be seen to be approximately tangentto the bead or the curved portion and it will be seen that it isinclined upwardly and inwardly toward the center of the cap.

In order to present a smooth surface for engaging the glass finish, aswell as to facilitate the manufacture of the hollow bead and detents,the upper or free end of the shank 20 is rolled or curved as indicatedat 21.

It will be seen that the uppermost end or portion 21 of each detent l5lies substantially above the top of the hollow bead 10, and alsosubstantially radially inwardly thereof. By virtue of being so placed,the upper end of each detent 15 is positioned so as to engage and gripeach glass container immediately under the rim or top finish, e.g. bead,thereof.

Certain proportions and related dimensions of the cap shell, hollow bead10 and the detents 15 are important and preferred proportions andrelationships exist. Referring to Fig. 4 it will be noted that theoverall height of the closure cap 6 is indicated by the dimension A; theheight of the detents 15 is indicated at B; while, the height (and alsothe diameter) of the hollow bead 10 is indicated at C. In general, thedimension B is approximately twice the dimension C. Furthermore, thedimension C is approximately one-third of the dimension A. By virtue ofsuch proportioning, together with the formation and contour of thedetents 15 and the hollow bead 10, the cap 6 is given a new type ofaction not previously obtained in press-on, top-seal closure caps. Thisnew action will now be further described in connection with Fig. 5 whichdepicts the relationship of parts and elements of the closure cap withrespect to the glass finish on the upper edge or rim of the container,this finish being designated generally at 22 in Fig. 5. It will be seenthat the finish 22 is embedded into the gasket 11 so as to displace thesame or bulge it up as it were, on opposite sides of the finish. Byreason of this relationship an excellent seal is obtained and anyvariations in the glass finish are accommodated for. It will also beseen that the detent 15, that is the shank 20 thereof, has been bent orsprung so that the upper free end 21 fits underneath the bead 23.

By reason of the hollow bead and detent construction the two followingfeatures are incorporated into the caps 6. First, the hollow bead sorigidifies the side wall or skirt 8 of the shell of the cap that the capas a whole has a high resistance to being deformed, bent or sprung whenpressure to pry off is applied underneath it at any one point. When thesealed container comes to the consumer and it is necessary to open itfor the first time, the cap 6 is retained on the container through thecombined forces of the vacuum in the headspace as well as the grippingof the detents underneath the bead 23. These two combined retainingforces must be overcome to remove the cap 6 from the container and thusgain access to the contents. However, the rigidity imparted by therather large hollow bead 10 is such that this together with the skirt 8provides sufficient rigidity to the shell so that upon being pried offat any one point, instead of permanently bending or distorting, thewhole cap gives all at once and snaps off as it were all away around.When the removed cap is examined it is not seen to be noticeably bent ordistorted.

Another feature is that the bead construction 10 in cooperation with thedetents 15 eo-acts to provide a detent gripping action with asubstantial amount of resilience built into it. In other words, each ofthe detents 15 in combination with the hollow bead lying on either sideof it, in effect acts as a spring finger extending from a coil spring.In other words, when the shank portion 20 of the detent is deformed byapplication of pressure on the upper end 21, the whole detent tends tobe inwardly deformed or curled as well as the bead lying adjacent eitherend of the detent. In fact, the hollow bead tends to roll up or tightenup. Therefore, a substantial resistance to deformation is built intoeach of the detents 15 and yet the detents can give or move to asubstantial degree without becoming permanently bent or set. Thus,maximum use is made of the normal springiness or resilience of thematerial to provide a firm but yielding gripp1ng action.

After the cap 6 has been removed, it can again'be manually reapplied andpressed down into place in substantially the same position andrelationship as shown in Fig. 5. While the re-seal will not be trulyhermetic, it will be fairly air tight and the cap 6 will be definitelyretained on the container. However, having once been opened and thevacuum having been broken, the cap may now be removed readily by hand.Hence, it may be snapped in place and removed at will as often asdesired. Accordingly, the cap has a very high degree of utility afterthe container or package has once been opened.

In Fig. 6 a second embodiment of the invention is shown in associationwith a different container. In this case the glass container indicatedgenerally at 25 does not have a bead at the top, however, it issufiiciently tapered or slanted to give much the same effect. In thiscase the cap is indicated generally at 26 and comprises a metal shellhaving a completely flat top panel portion 27 and a straight side wallor skirt portion 28. At the bottom edge a hollow bead construction isindicated at 3t] including a plurality of detents having shank portions31 and upper edges 32. If desired, the hollow bead construction 30 andthe detent formations included therein may correspond to the hollow bead10 and detent formations 15 described above in connection with cap 6 inFigs. 2-5.

Instead of having a flowed-in plastisol gasket, cap 26 has a preformedring gasket which may be formed of rubber or rubber-like materialsuitable for gasket purposes. This gasket is indicated at 33 and it maybe suitably adhered to the interior of the cap shell so as not to bedisplaced in handling or use. The cap 26 acts in generally the same wayas does cap 6. That is, it may be sprung oil from the closed containerwithout distortion or bending and may thereafter be reapplied andremoved as often as desired. The detents also serve to firmly grip theexterior of the glass container 25 and to retain the caps 26 thereon ina firm manner.

The detents in addition to retaining the caps on the containers, alsoserve to center or position the caps with respect to the glasscontainers both during original application in the closure applyingmachines as well as on manual reapplication of the closure caps afterhaving been initially removed.

It will be obvious that only a small portion of the area of each detentactually engages the side wall of the glass containers, this portionbeing the middle of the upper edge of each of the detents. Since thearea of contact is small, the pressure is relatively high. However, thisrelatively high pressure area of contact is completely surrounded orbacked up by a resilient structure as explained above, provided not onlyby each detent itself but also by the hollow bead construction lying onopposite sides of each detent.

It will be seen that tthe straightened out length of a hollow bead aswell as the straightened out length of the detents are alsosubstantially equal. This necessarily follows from the fact that asoriginally stamped or blanked out the side walls of the shells have thesame height all the way around. The first operation is to apply theslight inturn or curl 21 or 33 on the free edge of the side wall andthereafter the hollow bead and the intermediate detents are formed. Thisis all done on automatic machinery using suitable dies and fixtures ofknown type.

It will be understood that certain modifications and changes in detailsmay be made in the closure caps described above and illustrated in theaccompanying drawings without departing from the spirit and scope of theinvention.

What is claimed as new is:

l. A closure cap of the top seal type for use in establishing andmaintaining a hermetic seal on a glass container of the type in whichthe upper edge of the rim of the container constitutes a hermeticsealing finish; said cap comprising a cup-shaped shell having agenerally flat top panel portion and a depending skirt portion, and asealing gasket positioned within said shell for sealing engagement withsaid sealing finish when the cap is held down on the container; and saidskirt portion having a hollow inturned integral bead formed of the shellmaterial around the bottom thereof, said bead including a plurality ofapproximately equi-spaced detents for engaging the exterior of thecontainer below said sealing finish and thereby locating and retainingsaid closure cap on said container, said bead being substantially closedand generally circular in transverse crosssection intermediate saiddetents, and said detents being generally fishhook shaped in transversecross-section through the midportion thereof with the curved bottomportions having substantially the same radius of curvature as the bottomportion of said bead, and with the shank portions being approximatelytangent to said bottom curved portions and upwardly and inwardlyinclined toward the center of said cap whereby the uppermost end of eachdetent occupies a position substantially above and inside said bead,said head and detents having substantially equal straightened-outlengths at all cross-sections therethrough.

2. The closure cap called for in claim 1 wherein the upper free edges ofeach detent are curled over toward the outside of said cap so as toprovide a smooth inner surface on each detent.

3. The closure cap called for in claim 1 wherein the length of each ofsaid detents equals from about 5 to 7 percent of the inner circumferenceof said head.

4. The closure cap called for in claim 1 wherein the diameter of saidhead is approximately one-third of the overall height of said cap, andthe height of each detent is approximately twice said diameter.

References Cited in the file of this patent UNITED STATES PATENTS

